Anti-roll suspension valve body

ABSTRACT

A suspension system that restricts side-to-side airflow between air springs on opposite sides of a vehicle or trailer. In one embodiment, active airflow discs in suspension ports of a valve operate in two modes; restrictive and non-restrictive. A disc attains a non-restrictive mode when air is exhausted from an air spring. A disc attains a restrictive mode when air is injected into the suspension port from the valve toward an air spring. Airflow discs in opposing suspension ports both attain a non-restrictive state to rapidly dump air from the springs and lower vehicle ride height. In another embodiment, a pneumatic circuit includes one-way check valves, in fluid communication with opposing air springs, aligned to restrict airflow between the opposing springs under uneven loading conditions. A pair of electronic solenoids acts in concert with the check valves to selectively inflate or deflate the air springs.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a leveling system for a vehicle,and more particularly to a valve body for distributing air to suspensionelements.

[0002] Conventional leveling systems are installed in a wide variety ofvehicles ranging from passenger cars to semi-trucks and semi-trailers.The larger leveling systems typically include pneumatic suspensionelements, such as shocks or air springs, that can be inflated ordeflated to control the height of the frame with respect to the axle.For example, on semi-trailers, heavy loads can cause a suspension tosag, thereby decreasing the distance between the frame and the axle.Accordingly, the ride height of the trailer, that is, the distancebetween the trailer bed and the ground, may be reduced. In conventionalleveling systems, the ride height of the trailer may be adjusted byinflating or deflating the pneumatic suspension to compensate for theload. Specifically, when the ride height of a trailer has been affectedby a heavy or light load, the suspension elements can be inflated ordeflated to return the trailer to the desired ride height.

[0003] In leveling systems of the prior art, the height of thesuspension is controlled by mechanical height control valves including avalve assembly and a valve body. The valve assembly senses thefluctuations in the ride height due to loading and controls theinflation/deflation of the suspension elements through the valve body.Typically, the valve body is located within the leveling circuit betweena source of compressed air and the suspension elements. Duringoperation, the valve body typically is in a neutral or “closed” mode.Accordingly, air cannot enter or leave the leveling circuit. However,due to fluid communication between suspension elements on opposite sidesof the vehicle via the valve body, air may flow from a left side elementto a right side element when the left side element is excessivelyloaded-this is called “side-to-side” air transfer. Obviously, air mayflow from right to left when the right side is excessively loaded aswell.

[0004] Illustrated in FIG. 1 is an uneven loading situation resulting inside-to-side air transfer. A vehicle 110 traversing a corner has atendency to tilt or roll outward away from the “center” of the corner,due to centrifical force. During this tilting action, the right sideelements 104 are excessively compressed by the load being shiftedoutward. Due to the fluid communication between the left 102 and right104 side suspension elements, air is forced from right side suspensionelements 104, travels through the valve body 108, and into the left sidesuspension elements 102. As a consequence, the left side suspensionelements 102 extend and exacerbate the tilt or roll of the vehicle.Further, given the advent of larger airflow lines used in conventionalleveling circuits to promote quicker inflation/deflation of airsuspension elements, side-to-side air transfer is substantiallyincreased.

[0005] Illustrated in FIG. 2 is a valve body 115 of the prior art thatattempts to correct side-to-side transfer of air by placing a passiverestrictive element 112 within the valve body 115. Although the use ofthe restrictive element does limit the side-to-side transfer of air Aduring cornering, it creates a variety of problems. First, therestrictive element restricts (a) dumping of air from the suspensionelements, through the dump port 122 during deflation, and (b) injectionof air into the valve body 115 via the supply port 126, and consequentlyinto the suspension elements, during inflation. Second, dirt or debrisaccidentally entering the interior portion of the valve body, may becomelodged between the restrictive element and the valve body tosubstantially impede airflow through the valve body. Moreover, to removethe debris, the valve body must be detached from the valve assembly.

SUMMARY OF THE INVENTION

[0006] The aforementioned problems are overcome by the present inventionwherein the valve body of a height control leveling system is providedwith devices to actively restrict side-to-side transfer of air betweensuspension elements.

[0007] In one embodiment, a restrictive airflow disc is positioned ineach of the two suspension ports of a valve body to actively restrictside-to-side air transfer. The airflow disc is a thin, flat circularplate with an orifice through its center, and bypass orifices disposedaround the disc's circumference. A coil spring is attached to a firstside of the disc, and a sealing element is disposed around the centralorifice on a second side of the disc. In each of the suspension ports,the coil spring abuts an internal seat of the valve body and forces thesealing element in sealing engagement with a suspension fittingassociated with the air supply line coupled to the suspension port.

[0008] The disc has two modes; restrictive and non-restrictive. The discattains a non-restrictive mode when air, forcibly exhausted from an airspring, presses against the disc and compresses the coil spring. Thecompression of the spring causes the disc to move away from thesuspension fitting, and disengages the sealing element from thesuspension fitting, thereby allowing air to exhaust into the valve bodythrough the bypass orifices as well as the central orifice. The discattains a restrictive mode when air is injected into the suspension portfrom the valve body. The sealing engagement of the sealing elementagainst the suspension fitting is reinforced so that air enters thesuspension lines through the central orifice alone. Thus, when air isforced from a compressed suspension element during cornering to thevalve body through a suspension port, the airflow disc associated withthe suspension port connected to the compressed element attains anon-restrictive state; and air flows freely into the valve body.Conversely, when air passes through the valve body into the suspensionport associated with the suspension element on the opposing, unloadedside of the vehicle, the airflow causes the airflow disc in thatsuspension port to substantially obstruct the suspension port, so thatair cannot pass freely to the unloaded suspension port. Thus, at leastfor short periods of time, tilting or rolling is not exacerbated byside-to-side air transfer.

[0009] In another aspect of the invention, both airflow discs attain anonrestrictive state to promote rapid dumping of air simultaneously fromthe suspension elements to lower the ride height of the vehicle.

[0010] In a third aspect of the present invention, the airflow discs areeasily installed and maintained in conventional valve bodies. Theairflow discs are disposed within the suspension ports between aninternal seat of the valve body and an external fitting associated withan air supply line leading to the suspension elements.

[0011] In a second embodiment of the invention, a system or pneumaticcircuit of solenoids and one-way valves actively restrict side-to-sideair transfer. Suspension elements on opposite sides of a vehicle, asupply port and dump port are plumbed into a system including solenoidsand multiple check valves. A first solenoid may be selectively actuated(a) to allow air into the suspension elements through the supply port or(b) to prevent air from escaping the system through the supply port. Asecond solenoid may be selectively actuated (a) to dump air from thesuspension elements through the exhaust port or (b) to prevent air fromescaping the system through the exhaust port.

[0012] In this second embodiment, the check valves are oriented in thesystem so that when suspension elements on one side of the vehicleexhaust air therefrom, such as during cornering, that air is restrictedby the check valves and will not rapidly transfer through the system tothe suspension elements on the other side. The solenoids act in concertwith the check valves to restrict side-to-side transfer, and prevent airfrom being lost or input into the system during side-to-side transferand under even-load conditions.

[0013] The check valves also act in concert with the solenoids to supplyair to or dump air from the suspension elements. For example, whendumping air from the suspension elements, some of the check valvesattain a non-restricting state and act in concert with the exhaustsolenoid to allow air to dump from the system. Similarly, when supplyingair to the suspension elements, different check valves attain anon-restricting state and act in concert with the supply solenoid toallow air to enter the system and fill the suspension elements.

[0014] These and other objects, advantages, and features of theinvention will be readily understood and appreciated by reference to thedetailed description of the preferred embodiment and the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a perspective view of a vehicle suspension system duringcornering;

[0016]FIG. 2 is a sectional view of the prior art valve body with arestrictive body therein;

[0017]FIG. 3 is a plan view of the leveling system of the presentinvention;

[0018]FIG. 4 is a perspective view of the valve body;

[0019]FIG. 5 is a top plan view of an airflow disc of one embodiment;

[0020]FIG. 6 is a sectional view of the airflow disc taken along lines6-6 of FIG. 5;

[0021]FIG. 7 is a sectional view of a valve body with airflow discs whensuspension elements are in equilibrium;

[0022]FIG. 8 is a sectional view of the valve body with airflow discswhen the suspension elements are unevenly loaded;

[0023]FIG. 9 is a sectional view of the valve body with airflow discswhile inflating the suspension elements;

[0024]FIG. 10 is a sectional view of the valve body with airflow discswhile dumping the suspension elements;

[0025]FIG. 11 is a top plan view of an alternative embodiment of theairflow disc;

[0026]FIG. 12 is a side of view of an alternative embodiment of theairflow disc;

[0027]FIG. 13 is a schematic view of a second alternative embodiment ofthe leveling system incorporating a system of one-way valves andsolenoids;

[0028]FIG. 14 is a schematic view of a third alternative embodiment ofthe leveling system incorporating a system of one-way valves andsolenoids;

[0029]FIG. 15 is a schematic view of a fourth alternative embodiment ofthe leveling system incorporating a system of one-way valves andsolenoids;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0030] A valve body according to a first embodiment of the presentinvention is illustrated in FIGS. 3, 4 and 7-10 and generally designated10. For purposes of disclosure, the valve body 10 is described inconnection with a conventional leveling system where the valve mechanism30 couples to valve body 10 where the valve mechanism functions tocontrol the flow of air into and out of the suspension elements 42, 44through valve body 10 (see FIG. 3). The valve body is well suited foruse in a variety of other leveling systems besides suspension, such asconventional truck cab leveling systems designed to level the truck cabwith respect to the truck frame.

[0031] The leveling system of the present invention generally includesvalve body 10 coupled to a valve mechanism 30 including an actuator yoke33. The valve mechanism 30 is mounted to the vehicle frame 40 in aconventional manner and connected to the axle 46 or any other partsuspension via actuator yoke 33. The actuator yoke 33 may be mounted tovirtually any element that moves with the axle or to any portion of asuspension. Also, the valve mechanism 30 may be installed in reversewith a valve body secured to the axle (or other suspension-relatedelement). In other applications, such as a truck cab leveling system,the height control valve mechanism is mounted between the two componentsfor which relative movement is to be controlled.

[0032] With reference to FIGS. 4 and 7, part of the valve mechanism 30(not shown) extends into the internal bore 12 of valve body 10. As willbe appreciated by those skilled in the art, the valve mechanism controlsthe supply of air through the supply port 24 into the suspension ports16 and 18 as well as exhaust and dumping of air from the suspensionports 16 and 18 through dumping port 20 and exhaust port 22. For thesake of simplicity, the valve mechanism within the internal bore 12responsible for controlling the supply, dumping and exhaust of airthrough the valve body 10 has been omitted in FIGS. 7-10. To indicateopen and closed valves associated with the supply port and exhaust port,“Valve Open” and “Valve Closed” is indicated in FIGS. 7-10. As will beappreciated by those skilled in the art, the actual opening and closingof valves associated with these ports is controlled by the omitted valvemechanism.

[0033] As depicted in FIGS. 3 and 7, the valve body 10 includessuspension ports 16 and 18 which are connected to the suspensionelements 42 and 44 via air lines 32 and 34. Conventional suspensionfittings or air line fittings 17 and 19 are used suspension ports 16 and18. As will be appreciated by those skilled in the art, fittings mayinclude threaded fittings, snap-fit fittings, permanently connectedfittings, and other types of fittings. The fittings 17 and 19 arefurther connected to the air line 32 and 34, respectively, as depictedin FIG. 3. Accordingly, suspension elements 44 and 42 are in fluidcommunication with one another through the valve body 10. Screens 26 and27 may optionally be positioned in each of the suspension ports toprevent debris from entering the internal bore 12 of the valve body.These screens may be of any type or material as will be appreciated bythose skilled in the art. Each of the suspension ports 16 and 18 includeinternal seats 14 and 15. As depicted in FIGS. 7-10, the internal seatsare generally reductions in the diameter of the bore of each suspensionport 16 and 18; however, “internal seat” also includes any type ofprotrusion into the bore of the suspension port. The valve body 10 ismade out of plastic so that it is resistant to corrosion. The valve bodyalso may be made of metal or alloys as desired. The valve body of thepresent invention may be used in conjunction with multiple suspensionelements associated with multiple axles of a vehicle as will beappreciated by those skilled in the art. The spring elements 60, 80 ofthe airflow disc, 50, 70 seat against the internal seats 14 and 15 ofthe valve body 10. On the opposite faces of the disc plates 51, 71,sealing elements 54, 74 seal the airflow discs 50, 70 against thefittings 19 and 17.

[0034] As depicted in FIGS. 5 and 6, a first embodiment of the airflowdisc includes disc plate 51 and an orifice 52 defined by the approximatecenter of the disc plate 51. The orifice is any hole of any size orshape, depending on the desired air flow defined by the plate 51.Disposed concentrically around the orifice 52 is sealing element 54. A“sealing element” includes washers, o-rings, gaskets, integrated seals,or any other seals, made from rubber, plastic, silicone, cork, or anyother suitable material. Around the periphery of the disc plate 51 arebypass orifices 56. These orifices may be of any number or size orconfiguration depending on the desired flow of air that is bypassed. Onthe side of the disc plate 51 opposite the sealing element 54 andcontained by the spring guide flange 58 is spring element 60. The springelement may be a helical coil as depicted in FIG. 6, or any otherconfiguration, including that depicted in FIGS. 11 and 12 of a secondembodiment for an airflow disc where the spring elements are leaf prongs160 disposed around the outer circumference of the airflow disc plate151. Depending on the desired airflow, the spring element 60 of thepreferred embodiment may be of a predetermined elasticity. The airflowdisc 50 and all components thereof are preferably manufactured usingcorrosion resistant materials such as engineered polymers or elastomers.

Operation

[0035] The operation of the valve body of the present invention toprevent side-to-side air transfer while still providing rapid deflationof the suspension elements will now be described.

[0036]FIG. 7 illustrates the valve body of the preferred embodiment whenthe suspension elements are evenly loaded and thus in equilibrium. Theairflow discs 50 and 70 are disposed in each of the suspension ports 18and 16 so that the sealing elements 54, 74 abut against the fittings 19and 17 within the suspension ports. The sealing elements 54, 74 abut thefittings 19 and 17 to provide sealing engagement between the fittings 19and 17 and the airflow disc plates 51 and 71 respectively. The springelements 60, 80 bias the disc plates 51 and 71 to reinforce sealingengagement of the sealing elements 54, 74 between the disc plates 51 and71 and fittings 19 and 17. Because valves associated with the supplyport 24 and exhaust port 22 are closed, the system is in equilibrium.Accordingly, air is not transferred through the suspension ports 16and/or 18 into or out from the internal bore 12, the airflow discs 50and 70 remain abutting fittings 19 and 17.

[0037]FIG. 8 illustrates the airflow discs actively restrictingside-to-side air transfer. As discussed above, and illustrated in FIG.1, when a vehicle traverses a comer, the vehicle will tilt and,accordingly, unevenly load suspension elements on opposite sides of thevehicle. For example, the suspension element on the outside of a comerwill be compressed thus exhausting the air from that suspension elementthrough the suspension port the valve body. When air, depicted in FIG. 8as A, flows through the fitting 19, it forcefully pushes against thedisc plate 51. The spring element 60 thus is compressed and the discplate 51 is forced away from the fitting 19 whereby air A flows throughthe central orifice 52, as well as around the bypass orifices 56 intothe internal bore 12. Accordingly, the flow of air from the suspensionport is increased over that which it would be if air flowed through thecentral orifice alone.

[0038] Because the dump port 20, supply port 24 and exhaust port 22 areclosed, air cannot escape the internal bore 12 via the exhaust port 22or the supply port 24. Thus, the internal pressure of the internal bore12 raises and forces the airflow toward the opposing suspension port 16.As the air contacts the airflow disc in the left side suspension port16, the air forces the airflow disc 71 against the fitting 17 in thesuspension port 16. Accordingly, the sealing element 74 is pushed infurther sealing engagement against the fitting 17. Consequently, the airwithin the internal bore 12 may only pass through central orifice 72 ofthe disc plate 71; no air flows around bypass orifices 76. Notably,after extended periods of time, air passes through the central orificeand the suspension element on the “unloaded” side of the vehicleeventually fills with air.

[0039] The valve body of the present invention also provides forinflation of suspension elements on opposing sides of the vehicle toraise the ride height of the vehicle. As depicted in FIG. 9, air A froman air supply (not shown), is forced under pressure into supply port 24,as will be appreciated by those skilled in the art. The air enters theinternal bore 12 of the valve body 10. Because the valve (not shown)associated with exhaust port 22 is closed, air is prevented fromescaping internal bore 12 therethrough. Once air enters into theinternal bore 12, it is dispensed into the suspension ports 16 and 18.Because of the increased internal pressure, the air pushes the airflowdiscs 50 and 70 into sealing engagement with the fittings 17 and 19.Accordingly, air enters the fittings 17, 19, that are in fluidcommunication with the suspension elements on opposing sides of thevehicle (not shown) through internal orifices 52 and 72.

[0040] The valve body of the present invention also provides for rapiddumping of air from opposing suspension elements of a vehicle to lowerthe ride height of the vehicle. FIG. 10 depicts the valve body andassociated airflow discs 50 and 70 while simultaneously dumping air fromsuspension elements on opposing sides of a vehicle. To initiate dumping,the dump port 20 is pressurized by actuation of the valve mechanismwithin the internal bore 12, as will be appreciated by those skilled inthe art. The supply port 24 and dump port 20 remain closed duringdumping. Once the valve (not shown) is opened, air exits the suspensionelements through the suspension ports 16 and 18. Air exiting through thefittings 17 and 19 forcibly pushes against the disc plates 51 and 71.Accordingly, the airflow discs 50 and 70 are pushed inward, thuscompressing spring elements 60 and 80 simultaneously. With the springelements compressed, the air from the suspension ports 16 and 18 mayflow through bypass orifices 56 and 76 freely into the internal bore 12and out through the exhaust port 22. In this manner, the air flow issubstantially unrestricted so that the air may be dumped from thesuspension elements rapidly.

Alternative Embodiments

[0041] The airflow discs of the present invention may be used inconjunction with a dual suspension port valve body and alternativelywith a single suspension port valve body. In the single suspension portapplication, a modification of the preferred embodiment is required. AT-type connector is attached to the single suspension port to providefluid communication between that suspension port and suspension elementson opposite sides of the vehicle. For example, one part of the Tconnects to the single suspension port of the valve body, one part ofthe T connects to the left side suspension elements, and the third andlast part of the T connects to the right side suspension ports. Like thepreferred embodiment, airflow discs are disposed opposedly within theT-connector ports associated with the suspension elements in a fashionsimilar to that in the first embodiment side-to-side air transfer isrestricted in the same manner as in the first embodiment.

[0042] In a second, third and fourth embodiments of the presentinvention, a system or pneumatic circuit of one-way valves and solenoidsrestrict side-to-side transfer of air between opposing suspensionelements and additionally allows adequate supply and dumping of air fromthose elements. Generally, in these three embodiments, depicted in FIGS.13-15, right side suspension element 242 and left side element 244 arein fluid communication with conventional air supply reservoir 200 andconventional dump port 222 via: valve system 210 in the firstalternative embodiment depicted in FIG. 13; valve system 310 of thesecond alternative embodiment depicted in FIG. 14; and valve system 410of the third alternative embodiment depicted in FIG. 15. Although onlytwo suspension elements are depicted, any number of suspension elementson opposite sides of a vehicle or trailer may be plumbed into thesystem. The air reservoir 200 may be plumbed into any air supply device,such as a compressor. The dump port may be any commercially availableair outlet, which may or may not be restricted.

[0043] More particularly, with reference to the second alternativeembodiment of FIG. 13, suspension elements 242 and 244 are in fluidcommunication with valve system 210 via suspension lines 232 and 234.Suspension line 232 provides fluid communication between suspensionelement 242, preferably a right side suspension element or elements, andintermediate dump line 236 and intermediate supply line 238.

[0044] Intermediate right dump line 236 includes one-way valve 224,which preferably is a check valve, but may be any one-way valve thatrestricts or prevents flow in one direction and allows free flow in anopposite direction. As used herein “prevent,” when used with referenceto a one-way valve preventing fluid or air flow, means to stop air frompassing by the one-way valve to the extent it is feasible withconventional valves. In some cases, such as with a ball-bearing checkvalve, a minute amount of air may flow between the bearing and theinternal surface of the valve, even when the bearing is in itsrestricting state. In this case, the valve is still considered preventedby the valve. One-way valve 224 is oriented to allow air to flowunrestricted from intermediate right dump line 236 to dump solenoid line223, but restrict or prevent air from flowing from the dump solenoidline 223 back into intermediate right dump line 236. Preferably, theone-way valves used herein restrict airflow sufficiently so that no airpasses through those valves.

[0045] Intermediate right supply line 238 includes one-way valve 254,which preferably is a check valve, but may be any one-way valve thatrestricts or prevents flow in one direction and allows relatively freeflow in an opposite direction. One-way valve 254 is oriented to allowair to flow unrestricted from solenoid line 233 to intermediate rightsupply line 238 but restrict or prevent air from flowing from theintermediate right supply line back into right solenoid supply line 238.

[0046] As can be seen in FIG. 13, suspension line 234 provides fluidcommunication between suspension element 244, preferably a left sidesuspension element or elements, and intermediate left dump line 246 andintermediate left supply line 248. Intermediate left dump line 246includes one-way valve 225, which preferably is a check valve, but maybe any one-way valve that restricts or prevents flow in one directionand allows relatively free flow in an opposite direction. One-way valve225 is oriented to allow air to flow unrestricted from intermediate leftdump line 246 to dump solenoid line 223, but restricts or prevents airfrom flowing from the dump solenoid line 223 back into intermediate leftdump line 246.

[0047] Dump solenoid line 223 is in fluid communication withintermediate left and right dump lines 236 and 246, and dump solenoid220. The dump solenoid is preferably an electronic solenoid that may beactuated by an operator, such as a computer or human operator, toselectively allow air to pass freely from solenoid dump line 223 to dumpline 221 and out dump port 222. Air flowing from the suspension elementsthrough the valve system out the dump port, is referred to as “dumping”or “deflating.” As will be appreciated, any type of electronic orselectively actuatable valves may be substituted for the solenoids ofthe present invention.

[0048] Intermediate left supply line 248 includes one-way valve 255,which preferably is a check valve, but may be any one-way valve thatrestricts or prevents flow in one direction and allows relatively freeflow in an opposite direction. One-way valve 255 is oriented to allowair to flow unrestricted from supply solenoid line 233 to intermediateright supply line 248 but restrict or prevent air from flowing from theintermediate right supply line 248 into solenoid supply line 233.

[0049] Supply solenoid line 233 is in fluid communication withintermediate left and right supply lines 238 and 248, and supplysolenoid 230. The supply solenoid is preferably an electronic solenoidthat may be actuated by an operator, such as a computer or humanoperator, to selectively allow air to pass freely from air supply line231 through the solenoid 230, through the solenoid supply line 233 andinto right and left intermediate supply lines 238 and 248 respectively.Air flowing into the suspension elements through the valve system isreferred to as “filling” or “inflating.”

[0050] With reference to FIG. 13, the left 244 and right 242 suspensionelements are preferably in restricted fluid communication via a reliefsystem, several options of which are shown in dotted lines. This reliefsystem allows air to exhaust air from one side of suspension elements tothe other should the suspension elements of one side become excessivelyloaded. The use of one of this relief systems prevents damage, and insome cases rupture of excessively loaded suspension elements bytransferring air from those elements to others. Preferably, the reliefsystem includes a line including an orifice of a pre-selected diametertherein to selectively restrict flow of air through the line. Any typeof restricting device may be used. Optionally, the lines may themselvesbe of a pre-selected diameter to restrict flow.

[0051] In a first option, an orifice line 240 provides fluidcommunication between suspension lines 232 and 234. In a second option,bypass dump-side orifice lines 245 and 247 bypass one-way valves 224 and225 to allow restricted fluid communication between intermediate right236 and left 246 dump lines, and consequently restricted fluidcommunication between suspension lines 232 and 234. In a third option,bypass supply-side orifice lines 241 and 243 bypass one-way valves 254and 255 to allow restricted fluid communication between intermediateright 238 and left 248 supply lines, and consequently restricted fluidcommunication between suspension lines 232 and 234. Preferably, theorifices of the orifice lines of the present invention include internaldiameters that are about 0.001 to about 0.25 inches, more preferablyabout 0.01 to about 0.09 inches, and most preferably about 0.030 inches.Optionally, the orifices may be of any dimension or shape with an areaof 0.00001 square inches to 0.25 square inches.

[0052] In operation, the second alternative embodiment: (1) preventscompletely unrestricted side-to-side air transfer in suspension elementsof a vehicle or trailer; for example, from element 242 to element 244 orvice versa; (2) rapidly fills the suspension elements to increase rideheight; and (3) rapidly dumps air from the suspension elements to lowerride height. Under normal conditions, when the suspension elements andare under equal loads, the system is static, that is, fluid is neitherbeing input into the system or exiting from the system.

[0053] During cornering, one side of the vehicle is under a greater loaddue to tilt of the vehicle. Accordingly, one set of suspension elementsis loaded more and naturally attempts to expel air therefrom. Forexample, during a hard left turn, right suspension element 242 issubjected to a loading force, and compensates by expelling airtherefrom. With reference to FIG. 13, if suspension element 242 expelsair into suspension line 232, that air travels unrestricted into twoother lines; intermediate right dump line 236 and intermediate rightsupply line 238. Preferably, dump solenoid 220 and supply solenoid 230are not actuated and thus closed during operation of the vehicle toprevent air from being dumped or input into the valve system. With theconfiguration of the one-way valves in these two lines, air cannot betransferred directly, that is, unrestricted, through the intermediateright dump line 236 to the intermediate right supply line 238 or anyother line associated with the left side suspension elements. Thus,side-to-side air transfer is restricted. Similar restriction ofside-to-side transfer occurs when the vehicle comers to the right andair attempts to rapidly expel from the left suspension elements 244.

[0054] Notably, a small amount of air is transferred in restricted flowfrom the right suspension line 232 to the left suspension line viaorifice line 240, bypass dump-side orifice lines 245 and 247, and/orbypass supply-side orifice lines 241 and 243, depending on which ofthese options is implemented in the valve system 210. Because theseorifice lines are so restricting, a substantial amount of air cannotrapidly pass from the right suspension elements to the left suspensionelements and exacerbate tilt or roll of the vehicle.

[0055] To inflate the suspension elements with air, for example toincrease the ride height of the vehicle, supply solenoid 230 isactivated, and consequently air passes from reservoir 200, throughsupply line 231 and into solenoid supply line 233. Because one-wayvalves 254 and 255 do not restrict or prevent flow in a direction fromthe supply solenoid 230 to the intermediate right and left supply lines238 and 248 respectively, air freely flows into these lines, andconsequently inflates suspension elements 242 and 244. During thissupply of air into the suspension elements, the dump solenoid remainsclosed. Therefore, air does not flow out of the system through exhaustline 221.

[0056] To dump air from the suspension elements, dump solenoid 220 isactivated, and consequently air passes through the dump solenoid line223, the dump solenoid 220, dump line 221 and out dump port 222. Becauseone-way valves 224 and 225 do not restrict flow in a direction from theintermediate left and right dump lines 236 and 246 to the solenoid dumpline 223, air freely flows out through the dump port 222. During thisdumping of air from the suspension elements, the supply solenoid 230remains closed. Therefore, air does not flow into or out of the systemthrough supply line 231.

[0057] In the third alternative embodiment of the present invention, avalve system similar to the second embodiment is implemented. Withreference to FIG. 14, the valve system 310 of the third embodiment hassubstantially all of the same elements as the second embodiment of FIG.13, except the set of one-way valves associated with the intermediateleft and right dump lines 236 and 246 is replaced by a shuttle valve asdepicted. As will be appreciated, any valve may be substituted for theshuttle valve that prevents or restricts fluid communication betweenright intermediate dump line 236 and left intermediate dump line 246.Preferably, some sort of relief system such as orifice line 240 orsupply-side orifice bypass lines 241 and 243 are implemented in thisembodiment. As will be appreciated, the restriction of side-to-sidetransfer of air to/from suspension elements, the filling of suspensionelements, and the dumping of suspension elements all operate in a mannersimilar to the operation described in reference to the secondalternative embodiment and explained with reference to FIG. 13.

[0058] In the fourth alternative embodiment of the present invention, avalve system somewhat similar to the second embodiment is implemented.With reference to FIG. 15, the valve system 410 of the fourthalternative embodiment includes dump solenoid 220, related dump line 221and supply solenoid 230, with related supply line 231, as in the valvesystem 210 of the second embodiment. But unlike the second embodiment,dump solenoid line 423 is in fluid communication with supply solenoidline 433. These lines are further in fluid communication with rightsuspension line 232 and left suspension line 234. Additionally, rightsuspension line 232 includes one-way valve 454, which preferably is acheck valve, but may be any one-way valve that restricts or preventsflow in one direction and allows relatively free flow in an oppositedirection. One-way valve 454 is oriented to allow air to flowunrestricted from right suspension line 232 to supply solenoid line 433but restrict or prevent air from flowing from the solenoid supply line433 into right suspension line 232. Similarly, left suspension line 234includes one-way valve 455, which preferably is a check valve, but maybe any one-way valve that restricts or prevents flow in one directionand allows relatively free flow in an opposite direction. One-way valve455 is oriented to allow air to flow unrestricted from left suspensionline 234 into supply solenoid line 433 but restrict or prevent air fromflowing from solenoid supply line 433 into the left suspension line 234.

[0059] Right and left suspension lines preferably also include orificebypass lines 441 and 443 to allow restricted fluid communication betweenintermediate right 232 and left 234 supply lines, and consequently fluidcommunication between suspension lines 232 and 234. However, thesebypass orifice lines are somewhat larger than the orifice lines used inthe second and third embodiments described above. Preferably, theorifice bypass lines have internal diameters of about 0.005 to about 0.4inches, more preferably about 0.02 to about 0.1 inches, and mostpreferably about 0.050 inches. These bypass orifice lines are largerthan the orifice lines of the previous embodiments because they are usedalso to fill the suspension elements with air and increase the rideheight of the vehicle.

[0060] In operation, the fourth embodiment: (1) prevents completelyunrestricted side-to-side air transfer in suspension elements of avehicle, for example, from element 242 to element 244 or vice versa; (2)fills the suspension elements at a rate somewhat less than the rate ofthe previously described embodiments to increase ride height; and (3)rapidly dumps air from the suspension elements to lower ride height.Under normal conditions, when the suspension elements and are underequal loads, the system is static.

[0061] During cornering, for example, taking a hard left turn, rightsuspension element 242 would be subjected to a tremendous force, andwould try to compensate by expelling air therefrom. With reference toFIG. 15, if suspension element 242 expels air into suspension line 232,that air travels unrestricted through one-way valve 454. Thereafter, theair cannot go through one-way valve 455 and enter left side suspensionline 234, because that valve is forced closed to prevent air flowtherethrough. The air does not flow through supply solenoid line 433 ordump solenoid line 423 because the solenoids 220 and 230 are notactivated, and therefore prevent air from passing through them. However,air may optionally pass to the left side suspension element in arestricted flow through bypass orifice line 443.

[0062] Although bypass orifice line 443 substantially restricts flow,during extended periods when the right side suspension elements areexcessively loaded relative to the left side elements, the air fromthose right side elements will slowly flow into the left side elements.But, for periods of brief, excessive, uneven loading, such as duringcornering, typically encountered under normal driving conditions, thisfourth embodiment adequately restricts side-to-side air transfer. Ofcourse, the system would react in a similar manner under right corneringsituations when the left side elements are excessively loaded.

[0063] To fill the suspension elements with air, supply solenoid 230 isactivated, and consequently air passes from reservoir 200 and throughsupply line 433. From there, the air passes, in a restricted flow,through bypass orifice lines 441 and 443 into suspension lines 232 and234 to ultimately fill right 232 and left 244 suspension elements.During this supply of air into the suspension elements, the dumpsolenoid remains closed. Therefore, air does not flow out of the systemthrough exhaust line 221.

[0064] To dump air from the suspension elements, dump solenoid 220 isactivated, and consequently air passes through the dump solenoid line423, the dump solenoid 220, dump line 221 and out dump port 222. Becauseone-way valves 454 and 455 do not restrict flow in a direction from thesuspension lines 232 and 234 respectively, air freely flows out throughthe dump port 222. During this dumping of air from the suspensionelements, the supply solenoid 230 remains closed. Therefore, air doesnot flow into or out of the system through supply line 231.

[0065] The above descriptions are those of the preferred embodiments ofthe invention. Various alterations and changes can be made withoutdeparting from the spirit and broader aspects of the invention asdefined in the appended claims, which are to be interpreted inaccordance with the principles of patent law including the doctrine ofequivalents. Any references to claim elements in the singular, forexample, using the articles “a,” “an,” “the,” or “said,” is not to beconstrued as limiting the element to the singular.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A valve assembly forregulating fluid flow comprising: a first port; a second port in fluidcommunication with said first port; a first restrictor body engageablebetween a restrictive mode and a bypass mode, said bypass mode allowinga larger volume of fluid to pass by said first restrictor body than saidrestrictive mode, said first restrictor body disposed proximate saidfirst port and in fluid communication therewith; a second restrictorbody engageable between a restrictive mode and a bypass mode, saidbypass mode allowing a larger volume of fluid to pass by said secondrestrictor body than said restrictive mode, said second restrictor bodydisposed proximate said second port and in fluid communicationtherewith; and a conduit capable of exhausting fluid into said firstsuspension port whereby said first restrictor body attains a bypass modeand said second restrictor body attains a restrictive mode.
 2. The valveassembly for regulating fluid flow of claim 1 wherein said firstrestrictor body includes a first plate portion defining a first orificeand at least one first bypass orifice.
 3. The valve assembly forregulating fluid flow of claim 2 wherein said second restrictor bodyincludes a second plate portion defining a first orifice and at leastone first bypass orifice.
 4. The valve assembly for regulating fluidflow of claim 2 wherein a first sealing element is disposed on a firstside of said first plate portion and a first spring element is disposedon a second side of said first plate portion.
 5. The valve assembly forregulating fluid flow of claim 3 wherein a second sealing element isdisposed on a first side of said second plate portion and a secondspring element is disposed on a second side of said second plateportion.
 6. The valve assembly for regulating fluid flow of claim 4comprising a first fitting coupled to said first port and a secondfitting coupled to said second port, said first fitting in fluidcommunication with at least one suspension element on a first side of avehicle, said second fitting in fluid communication with at least onesecond suspension element on an opposite side of the vehicle.
 7. Thevalve assembly for regulating fluid flow of claim 5 wherein said firstrestrictor body attains said bypass mode when said first suspensionelement is loaded to a degree greater than said second suspensionelement.
 8. The valve assembly for regulating fluid flow of claim 6wherein said sealing element is in sealing engagement with said firstfitting and said second sealing element is in sealing engagement withsaid second fitting.
 9. The valve assembly for regulating fluid flow ofclaim 7 wherein said bypass mode of said first restrictor body is theresult of fluid exiting from said first fitting and impinging on saidfirst side of said first plate portion with such force that said firstspring element is compressed and said first sealing element is displacedfrom sealing engagement with said first fitting, whereby fluid iscapable of flowing through said first orifice and at least one of saidfirst bypass orifices.
 10. The valve assembly for regulating fluid flowof claim 8 wherein said restrictive mode of said second restrictor bodyis the result of fluid flowing from said first port to said second port,the fluid impinging upon said second side of said plate portion wherebythe sealing engagement of said second sealing element against saidsecond fitting is reinforced so that fluid flows into said secondfitting through said second orifice alone.
 11. A valve for regulatingair transferred between first and second suspension elements comprising:a first port in fluid communication with the first suspension element; afirst airflow restrictor disposed between said first port and the firstsuspension element, said first airflow restrictor engageable between arestricting and a non-restricting mode, said non-restricting modeallowing more air to pass by said first airflow restrictor than saidrestricting mode; a second port in fluid communication with first portand the second suspension element; and a second airflow restrictordisposed between the second suspension element and said secondsuspension port, said second airflow restrictor engagable between arestricting mode and a non-restricting mode wherein said non-restrictingmode allows more air to pass by said second airflow restrictor than saidrestricting mode.
 12. The valve body of claim 11 wherein said firstairflow restrictor engages to said non-restricting mode when fluid istransferred from the first suspension element toward said first port.13. The valve body of claim 12 wherein said second airflow restrictorengages to said restricting mode when fluid is transferred from saidfirst port toward said second port, whereby fluid communication betweenthe first suspension element and the second suspension element issubstantially restricted.
 14. The valve body of claim 13 wherein saidfirst and second airflow restrictors engage to non-restricting modeswhen air is simultaneously dumped from the first and second suspensionelements.
 15. A fluid flow restriction plate for ports in fluidsuspension systems comprising: a plate portion including a periphery, anorifice defined by said plate portion, said plate portion furtherdefining a plurality of bypass orifices; and a biasing element coupledto a first side of said plate portion.
 16. The fluid flow restrictionplate of claim 2 comprising a sealing element disposed around saidorifice on a second side of said plate portion.
 17. The fluid flowrestriction plate of claim 15 wherein said biasing element is a coilspring.
 18. The fluid flow restriction plate of claim 15 wherein saidbiasing element includes a plurality of biasing prongs extending fromsaid plate portion.
 19. The fluid flow restriction plate of claim 15wherein said fluid flow restriction body is corrosion resistant.
 20. Thefluid flow restriction plate of claim 15 wherein said plate portion isdisposed in at least one suspension port of a suspension levelingsystem.
 21. The fluid flow restriction plate of claim 15 comprising anannular protrusion on said first side which is arranged to retain saidbiasing element.
 22. A system for restricting side-to-side air transferbetween first and second suspension elements on opposite sides of avehicle comprising: a first one-way valve, in fluid communication withthe first suspension element and the second suspension element, orientedto allow fluid flow from the first suspension element and to preventfluid flow from the second suspension element to the first suspensionelement; a second one-way valve, in fluid communication with the firstsuspension element and the second suspension element, oriented to allowfluid flow from the second suspension element and to prevent fluid flowfrom the first suspension element to the second suspension element; andmeans for allowing restricted fluid communication between the firstsuspension element and the second suspension element.
 23. The system ofclaim 22 comprising means for deflating the first suspension element andthe second suspension element in fluid communication with the firstsuspension element and the second suspension element, said deflatingmeans actuatable between a first static mode and a deflating mode. 24.The system of claim 23 wherein said first one-way valve allowsunrestricted fluid flow from the first suspension element when saiddeflating means is in said deflating mode whereby fluid is rapidlydumped from the first suspension element.
 25. The system of claim 24wherein said second one-way valve allows unrestricted fluid flow fromthe second suspension element when said deflating means is in saiddeflating mode whereby fluid is rapidly dumped from the secondsuspension element.
 26. The system of claim 22 comprising means forinflating the first suspension element and the second suspension elementin fluid communication with the first suspension element and the secondsuspension element, said inflating means actuatable between a secondstatic mode and an inflating mode.
 27. The system of claim 26 comprisinga third one-way valve, in fluid communication with the first suspensionelement, oriented to allow fluid flow to the first suspension elementfrom the inflating means and to prevent fluid flow from the firstsuspension element.
 28. The system of claim 27 wherein said thirdone-way valve allows unrestricted fluid flow to the first suspensionelement from said inflating means when said inflating means is in saidinflating mode whereby fluid is rapidly filled into the first suspensionelement.
 29. The system of claim 28 comprising a fourth one-way valve,in fluid communication with the second suspension element, oriented toallow fluid flow to the second suspension element from the inflatingmeans, and to prevent fluid flow from the second suspension element. 30.The system of claim 29 wherein said fourth one-way valve allowsunrestricted fluid flow to the second suspension element from theinflating means when said inflating means is in said inflating modewhereby fluid is rapidly filled into the second suspension element. 31.The system of claim 30 wherein said first one-way valve is a checkvalve, said second one-way valve is a check valve, said third one-wayvalve is a check valve, and said fourth one-way valve is a check valve.32. The system of claim 30 wherein said third one-way valve is a checkvalve, said fourth one-way valve is a check valve and said first one-wayvalve and said second one-way valve are included in a shuttle valve. 33.The system of claim 22 wherein said restricted fluid communication meansincludes a first bypass line that bypasses said first one-way valve anda second bypass line that bypasses said second one-way valve.
 34. Thesystem of claim 33 wherein said first bypass line and said second bypassline each include orifices that restrict airflow through said firstbypass line and said second bypass line.
 35. The system of claim 22wherein said restricted fluid communication means includes a thirdbypass line that bypasses said third one-way valve and a fourth bypassline that bypasses said fourth one-way valve.
 36. The system of claim 33wherein said third bypass line and said fourth bypass line each includeorifices that restrict airflow through said third bypass line and saidfourth bypass line.
 37. The system of claim 23 wherein said deflatingmeans includes a deflating solenoid that attains said deflating modewhen powered and attains said first static mode when not powered. 38.The system of claim 26 wherein said inflating means includes a inflatingsolenoid that attains said inflating mode when powered and attains saidsecond static mode when not powered.
 39. A suspension system forregulating transfer of air between suspension elements on opposite sidesof one chosen from a semi-truck and a trailer, comprising: a first airspring for mounting on a first side of a vehicle including a firstspring line; a second spring for mounting on a second side of a vehicle,opposite said first side, including a second spring line; supply meansin fluid communication with said first spring line and said secondspring line for filling with air said first air spring and said secondair spring; dumping means in fluid communication with said first springline and said second spring line for dumping air from said first airspring and said second air spring; a pneumatic circuit in fluidcommunication with said first spring line, said second spring line, saidsupply means and said dumping means including a plurality of one-wayvalves oriented to selectively allow air to be filled into said firstair spring and said second air spring, to selectively allow air to bedumped from said first air spring and said second air spring, but toprevent air from passing from said first air spring to said second airspring when the one chosen from a semi-truck and a trailer traverses acomer in operation.
 40. The system of claim 39 wherein said dumpingmeans includes a dumping solenoid that operates in one chosen from adumping mode wherein air is dumped from said first and second airsprings and a dumping static mode, wherein air cannot exit through saiddumping means from said first and second air springs.
 41. The system ofclaim 40 wherein said supply means includes a supply solenoid thatoperates in one chosen from a supply mode wherein air is fed into saidfirst and second air springs and a supply static mode, wherein aircannot exit through said supply means from said first and second airsprings.
 42. The system of claim 39 comprising at least one relief linethat provides restricted fluid communication between said first and saidsecond air springs to prevent one of said first and said second airsprings from rupturing when said one of said first and said second airsprings is loaded more than the other air spring to the extent that saidloaded one of said first and said second air springs will be damagedunless air is communicated therefrom to the other air spring.
 43. Apneumatic circuit for air springs on a trailer or vehicle having a rideheight comprising: a supply regulator for raising the ride height of thevehicle or trailer when said supply regulator is actuated; a dumpregulator for lowering the ride height of the vehicle or trailer whensaid dump regulator is actuated; a first suspension element in fluidcommunication with said supply regulator and said dump regulator; asecond suspension element in fluid communication with said supplyregulator and said dump regulator; and a circuit of a plurality ofone-way valves in fluid communication with said supply regulator, saiddump regulator, said first suspension element and said second suspensionelement, and oriented to prevent air from transferring from said firstsuspension element to said second suspension element and vice versa, toselectively allow the dump regulator to lower the ride height of thevehicle or trailer when actuated, and to selectively allow the supplyregulator to raise the ride height of the vehicle when actuated.
 44. Thepneumatic circuit of claim 43 comprising at least one relief line thatprovides restricted fluid communication between said first suspensionelement and said second suspension element so that one of said firstsuspension element and said second suspension element does not rupturewhen excessively loaded.
 45. The pneumatic circuit of claim 44 whereinsaid plurality of one-way valves includes a first one-way valve orientedto allow fluid flow from the first suspension element and to preventfluid flow from the second suspension element to the first suspensionelement and a second one-way valve, in fluid communication with thefirst suspension element and the second suspension element, oriented toallow fluid flow from the second suspension element and to prevent fluidflow from the first suspension element to the second suspension element.46. The pneumatic circuit of claim 45 wherein said plurality of one-wayvalves includes a third one-way valve, in fluid communication with thefirst suspension element, oriented to allow fluid flow to the firstsuspension element from the supply regulator and to prevent fluid flowfrom the first suspension element.
 47. The pneumatic circuit of claim 46wherein said third one-way valve allows unrestricted fluid flow to thefirst suspension element from said supply regulator when said rideheight is raised.
 48. The pneumatic circuit of claim 47 wherein saidplurality of one-way valves includes a fourth one-way valve in fluidcommunication with the second suspension element, oriented to allowfluid flow to the second suspension element from the supply regulatorand to prevent fluid flow from the second suspension element.
 49. Thepneumatic circuit of claim 48 wherein said fourth one-way valve allowsunrestricted fluid flow to the first suspension element from said supplyregulator when said ride height is raised.